POINT LOMA  As Ken Franke of the San Diego-based Sportfishing Association of California continues to deal with Mexico’s sudden and unforeseen banning of bluefin tuna fishing, sports boats scrambled to salvage trips to Mexican waters and make catches in U.S. waters.

Bluefin, yellowfin, dorado and yellowtail are in U.S. waters in growing numbers, with some reported as close as 12 miles off Point Loma.

Buoyed by the good news of fish getting closer, Franke said he will keep trying to get answers from Mexico on why the country shut down bluefin tuna fishing at the height of the summer season. And it’s not just for San Diego-based sport boats, but all boats — even Mexican vessels — in Mexico.

“We need to see more science-based studies to show what the current biomass is for bluefin tuna,” Franke said. “The stock assessment is based on how many fish are caught. But we see tons and tons of bluefin that don’t bite. We hope to see more science.”

In recent weeks, the Pew Charitable Trusts issued a scientific report that details how the Pacific bluefin tuna is in trouble from decades of overfishing. Pew claims that the population of bluefin tuna is 4 percent of its original or virgin, unfished size, according to the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean. Fewer than 40,000 adult bluefin (more than 44 pounds) remain in the Pacific, the study reports, and the catch rate of juveniles (fish under 2.2 pounds) threatens the bluefin’s existence in the Pacific.

In a blueprint to save bluefin, Pew is calling for a massive reduction in take and wants a minimum size of 44 pounds put on the species. It predicts that if changes are made, bluefin can rebound within five years.

“To allow the Pacific bluefin population to recover, fishing nations must take immediate and comprehensive action, including the establishment and implementation of catch limits based on the best available science and a minimum size limit to protect juvenile fish,” the statement from Pew said.

Pew went on to say that large purse seiners in the eastern Pacific off Mexico catch schools of juvenile bluefin that are taken to tuna pens or ranches on the coast of Baja. They’re fattened for months until they reach market conditions for sale.

In the western Pacific, fish are targeted at every age because of the value of the product. Pacific bluefin fetch big money, with one 507-pounder selling for $70,000. In past years, bluefin have sold for as much as $1.76 million in Tokyo.

It’s unclear if Mexico is using the Pew model as its reason for banning bluefin tuna fishing, but not even Pew is calling for a complete shutdown.

It will be up to Franke and SAC and others to figure out Mexico’s reasoning for closing off bluefin after its seiners and others got their fill for the tuna pens off the Mexican coast. Getting to the truth on fishery matters in Mexico has been very difficult for Americans to do in recent years.

When it comes to fishing regulations, visas for anglers and the like, Mexico has marched to the beat of its own drummer, and it seems that nothing the U.S. can do will change that.